Water‐Based Paintable LiCoO2 Microelectrodes: A High‐Rate Li‐Ion Battery Free of Conductive and Binder Additives

Abstract

AbstractA simple, low‐cost, and environmentally friendly water‐based colloidal spray‐painting process is developed to obtain mechanically stable microelectrodes of pure LiCoO2 on stainless steel disks, which display reversible high‐rate discharge capacity and good cyclability. By using a simple nanostructuring process with commercially available LiCoO2, the use of dispersant, conductive, and binder additives during the electrode preparation is completely avoided. The nanostructuring approach is based on: i) planetary ball milling and annealing of LiCoO2 microparticles and ii) LiCoO2 surface modification through dissociative H2O adsorption during contact with air‐ and water‐based colloid preparation. The coating technique involves: i) water‐based colloid preparation, ii) spray‐coating, and iii) post‐treatment (drying and calcination) processes. The effects of particle size distribution, shape, crystallinity, specific surface area, and LiCoO2 surface modification on the electrode architecture (roughness, thickness, packing density, and porosity) are studied, together with their impact on the final electrochemical performances of batteries assembled with such a LiCoO2 electrode.